JP2007513375A - display - Google Patents

Abstract

A display device having an image output surface on which an image is displayed as an array of pixel elements spaced apart, and a light transmissive element having a viewing surface, arranged to receive light from the display device, and receiving the received light A light transmissive element for displaying on the field plane, the light transmissive element having a polarizing layer disposed in an optical path between the display device and the field plane, wherein the polarizing layer is external to the display. A display arranged to attenuate unpolarized ambient light received from the display while substantially transmitting polarized light received from the display device.

Description

  The present invention relates to a display.

  Technologies related to flat panel displays such as liquid crystal displays (LCDs) and plasma displays have evolved to a stage where a single display can be economically manufactured to the screen size of a medium-sized home television set. Attempting to increase the display size of a single unit display above the above levels results in higher costs, lower yields, and other significant technical problems.

  Therefore, in order to provide a larger display, a hybrid technology has been developed in which a large number of small rectangular displays are gridded to form the required overall size. For example, a 2x2 grid array of 15 inch diagonal displays with electronics properly addressed so that pixel information is sent to the appropriate sub-display provides a 30 inch diagonal display Will do.

  A drawback of the above type of device is that the active area of the individual display, ie the area in front of the display where the pixel information is displayed, does not extend to the very edge of the physical area of the display. Technologies used for plasma, liquid crystal, etc. require that small edges around the edges of the active display area provide interconnections to the individual pixel elements and seal the back to the front substrate. This edge can be as small as a few millimeters, but it still creates an unsightly black strip across the gridded display.

  Various solutions have been proposed for this problem, many of which are bulk or fiber optic image guides that transform or expand the image generated in the active area of the individual sub-displays. based on.

For example, in Patent Document 1 (inventor Hilsum), by connecting the expanded images, the cut between the two adjacent panels formed in the region of the edge of the two panels is not visible. A wedge-shaped image guide is used that is formed from a bundle of optical fibers that extend the image produced on the panel display. The input end of each fiber is the same size or smaller than the pixel element. The optical fibers are arranged with the individual pixel elements of the panel display at the input end of the optical fiber so that the pixel structure of the display is carried over to the output plane of the image expander. Other image guides formed in the above manner may transform the image to provide an edgeless joint between a set of adjacent panels. Various types of light transmission guides may be used, such as a rigid or semi-rigid light transmission guide. For simplicity of manufacture, it has been proposed that the image guide can also be manufactured from a polymer material.
U.S. Pat. No. 4,139,261

  In use, ambient light from outside the display, which strikes the field of view of the depicted display screen, is directed under the image guide inside the display device. A portion of this ambient light may be reflected by the Fresnel reflection at the channel at the input end of the image guide and the air boundary and will be reflected to the viewer through the image guide. Accordingly, the contrast of the displayed image is undesirably reduced.

  One aspect of the present invention is a display device having an image output surface on which an image is displayed as an array of pixel elements spaced apart, and a light-transmitting element having a field surface so as to receive light from the display device. A light transmissive element disposed and displaying received light on the field plane, the light transmissive element having a polarizing layer disposed in an optical path between the display device and the field plane; The polarizing layer provides a display arranged to attenuate unpolarized ambient light received from outside the display while substantially transmitting polarized light received from the display device.

  This device attenuates unpolarized ambient light while providing a polarizing plate that sufficiently maintains the intensity of polarized light emitted from the display device, thereby providing ambient light for image quality at the image output surface of the display. Advantageously reduce the effects of

  In order for an LCD based display to display an image in which the pixels are intended such that the same pixels exhibit the same brightness, the LCD panel should be illuminated uniformly over the entire active area. However, since some areas of the backlight device do not emit light, light emitting elements such as light emitting lamps within the backlight device do not provide uniform illumination over the entire area of the backlight. This is because the light-emitting elements include non-light-emitting portions and need to be separated between the end electrodes of adjacent lamps, so that the light-emitting elements cannot be provided directly next to each other.

  One embodiment of the present invention includes a backlight having a light-emitting region and a non-light-emitting region, a modulator arranged to receive light emitted from the backlight, and light emitted from the light-emitting region of the backlight And a light redirecting means arranged to redirect a portion of the light source onto the modulator area closely related to the non-light emitting area of the backlight.

  This device provides a more uniform brightness at the image output surface of the display, while modulating a modulator such as an LCD panel that does not substantially reduce the average intensity of illumination across the surface of the modulator. The uniformity of the illumination provided by the backlight is advantageously improved.

  In attaching the LCD panel and the image guide to each other, it is highly desirable that the LCD panel be accurately positioned with respect to the input surface of the image guide. For operational reasons, the LCD should ideally not be glued to a transparent adhesive to the image guide (the glue is a component that can be repaired and cleaned without scratching). Instead, it should be mechanically held in close proximity to the image guide and with respect to positioning. Furthermore, it should be noted that the expansion coefficient of the LCD glass is significantly lower than that of the polymer material image guide. It is also important that this difference in expansion does not cause the level of stress experienced by the LCD, which causes LCD distortion in the temperature range in which the display is required to operate.

  One aspect of the present invention is a display panel having an image output surface on which an image is displayed as an array of pixel elements spaced apart, and a light transmission guide each having an input end and an output end, wherein the input end is An image guide having a plurality of light transmission guides arranged to receive light from each group of one or more pixel elements, the base frame surrounding the input end, and an opening, wherein the base frame is firmly attached to the base frame A first frame attached to the display frame, the display panel having a first frame disposed with respect to the image guide within the opening of the first frame, and an opening smaller than the first frame; Overlaying the display panel and applying pressure to the display panel, thereby causing the display panel to A second frame for holding so as to approach the guide, to provide a display having a second frame which is elastically coupled to the first frame.

  This device advantageously provides a robust but not permanent mechanism for securing a display panel, such as an LCD panel, and an image guide that does not scratch both the display panel and the image guide.

  In order to allow the input of the image guide to be accurately arranged in a large array of pixel elements on the panel display, the input end of the light transmissive guide is the correct relative position, often it is the position of the pixel. Suitably, it is maintained in a rectangular array. Whatever means is used to position the input end of the light transmissive guide in the correct relative position, problems can arise if the temperature of the display device changes.

Most commonly, panel displays are made from glass and related materials. The surface of the panel display may have a thin layer or film (eg, a polarizing filter in a liquid crystal (LC) display) bonded (eg, bonded) to the panel display. The layer may have a thermal expansion characteristic that is different from the thermal expansion characteristic of the underlying surface. Of course, this is a scene where the layer will expand or contact (eg, stretch or compress) with the underlying surface when the underlying surface expands in response to temperature changes. Those skilled in the art will understand. The image guides that have been proposed so far are relative to the input end of the light transmissive guide for the light transmissive guide and / or for the device (and if one of the above is used). There is a tendency to use polymer materials to match the correct position. Therefore, a problem arises because the thermal expansion characteristics of glass and polymer material are different.

  As an example, consider a display in which the input end of the image guide and the display substrate have different coefficients of thermal expansion, and the image guide expands over one pixel width beyond the panel substrate. This can have two main effects on the image displayed at the output of the image guide.

  The first is a change in the spatial resolution of the display. At locations within the display area, some light transmissive guides may receive substantially the same amount of light from two adjacent pixel elements. This has a low-pass spatial filter effect on the displayed image, and this effect will vary across the display area.

  Secondly, the outermost light transmissive guide extends beyond the display area of the panel and therefore will not receive any light. This creates an unsightly black line in the output of the image guide.

  One aspect of the invention is a display device having an image output surface on which an image is displayed as an array of spaced pixel elements, coupled to the image output surface of the display device, each having an input end and an output end. An image guide having a plurality of light transmission guides, wherein the input ends of the light transmission guides are mutually connected such that one or more groups of the light transmission guides receive light from each of one or more groups of pixel elements. A display with a relatively arranged image guide, wherein the display has an input end of the light transmission guide at an outer edge of the cluster with respect to a cluster having at least one subset of the light transmission guide. Has optical characteristics substantially similar to the optical characteristics of the light transmission guide and receives light from the image output surface of the display. And an inner frame having an input surface arranged so as to be surrounded by an outer frame having a thermal expansion characteristic substantially similar to the thermal expansion characteristic of the light transmission guide. A reflective layer that is optically coupled to the light transmission guide of the inner frame and covers at least the surface of the inner frame at a position opposite to the input surface of the inner frame and the surface of the inner frame adjacent to the outer frame. Then, the light that enters the inner frame and strikes the reflective layer passes through the inner frame that is optically coupled to an adjacent light transmission guide or through the input surface of the inner frame. Provide a display that reflects off the screen.

  This apparatus advantageously improves the optical properties of an array of light transmission guides coupled to another optically different frame and coupled to a frame that is optically similar to the light transmission guide. The reflective layer helps to recycle rather than absorb light entering an optically similar frame so that the operation of the light transmission guide and inner frame does not depend on the optical properties of the outer frame. This also helps increase design freedom.

  The front face of the tiled display screen consists of a number of image guides each having a number of light transmissive guides which may be made of a polymer material. In order to construct a large tiled array, a solid framework should preferably be provided to support the image guide and keep the image guide in close proximity. Typical materials (eg, polymers) used to make image guides are relatively low stiffness, fragile long-term stability, and the large size required to provide sufficient strength for large display screens. Because of the crossing area, it is not ideal as a material constituting the above structure. Although a metal or reinforced plastic framework is a more suitable solution, the different coefficients of thermal expansion cause the stress on the front viewing plane due to thermal expansion to be excessive.

  If stronger materials with substantially different coefficients of thermal expansion are employed, the image guide is supported and accurately aligned without imposing excessive internal stress on the front viewing surface or support frame. Means are required.

  The front faces of the individual image guides are preferably held with tight tolerances in a single plane to ensure that there are no visible steps between the front faces of the different image guides. Even small changes from the nominal plane of the front viewing plane will appear to the eye as a seam between display modules.

  More preferably, the image guides should be constrained in such a way as to prevent grooves between the image guides in the operating temperature range of the display.

  One aspect of the present invention is a base frame having a plurality of light transmission guides having input and output ends, and a thermal expansion coefficient that substantially matches a thermal expansion coefficient of the light transmission guide, A plurality of image guides each having a base frame surrounding an input end; means for coupling the plurality of image guides to an array in which an output surface of the image guide forms a continuous surface; and more than the base frame A support frame that is rigid and has a coefficient of thermal expansion different from that of the base frame, wherein the relative movement in a plane substantially parallel to the output surface of the image guide between the base frame and the support frame; There is provided a display having a support frame for coupling the base frame to the support frame by allowing connecting means.

  This arrangement is a substantially robust framework that couples the array of display panels together while providing sufficient tolerance for different thermal expansions between the elements of the tiled array in the operating temperature range required for the display. It advantageously provides a mechanism for construction.

  Display screens are required to meet certain minimum standards for radiated electromagnetic energy. To meet this standard, display screens are often equipped with a transparent conductive layer attached to the front of the display and coupled to a conductive shield to form a complete containment around the screen electronics.

  One aspect of the invention is a display device having an image output surface on which an image is displayed as an array of spaced pixel elements, coupled to the image output surface of the display device, each having an input end and an output end. An image guide having a plurality of light transmission guides, wherein input ends of the light transmission guides are disposed relative to each other, so that a group of one or more light transmission guides includes one or more pixel elements. And an image guide that receives light from each individual population of the plurality of electrically conductive materials between at least a portion of the length of the light transmissive guide, The electrically conductive material is disposed to absorb electromagnetic waves emitted from the display device, and the image It said electrically conductive material between the light transmission guides discrete regions Id provides a display that is electrically connected to one another.

  The device uses electrically conductive material that is connected to each other and distributed between the light transmissive guides across the display image guide, which helps to attenuate the blocked electromagnetic radiation. This advantageously provides a mechanism for absorbing electromagnetic radiation emanating from the internal circuitry of the display device.

  As described above, a larger display can be manufactured by arranging the display panels in a tile shape. With appropriate drive electronics, a portion of the entire image can be applied to each display panel so that the tiled display displays the entire image.

  However, if the individual display panels are controlled separately by the drive electronics associated with the individual display panels, some of the images displayed on the separate display panels are updated to new frames at different times. Visual artifacts will occur at the boundaries between display panels.

  Motion artifacts can be hidden or removed using image processing of successive image frames (eg, time interpolation) or generating a one frame time delay between each column of the panel. . The latter method may include, for example, starting frame 1 in the third column when the top column of the tiled display starts frame 3. This satisfies avoiding discontinuities at the boundaries between columns without turning the LCD panel upside down, but creates a visible 'tilt' of the image as it moves, It causes lip sync problems in the display's sound system. This is because the lower row displays an image that was displayed a few frames (possibly hundreds of milliseconds on a large display) at the top row.

  One aspect of the present invention is a multiple display panel formed into multiple columns and arranged to form a single image output surface, each display capable of displaying multiple lines of pixels, and a refresh pattern A tiled display having display control means arranged to refresh each display panel on a line-by-line basis, wherein the set of refresh patterns adjacent in the vertical direction of the display panel comprises: A tiled display having a refresh pattern such that a lower area of the set of upper display panels is refreshed substantially simultaneously with an upper area of the set of lower display panels being refreshed. provide.

  This device can detect perceived visual artifacts caused by refreshing adjacent portions of vertically adjacent display panels at different times, in the refresh direction between one column of the panel and the next column. , Advantageously by switching from a top-to-bottom refresh to a bottom-to-top refresh, so that adjacent portions of vertically adjacent display panels are refreshed substantially simultaneously.

  The display may use a backlight and one or more light modulation or image transformation devices between the backlight and the output surface of the display. At each of the boundaries between components in the optical path from the backlight to the image output surface, there will be insertion (reflection) and loss of transmitted light due to Fresnel reflection. In addition, the above boundaries and other reflective surfaces in the display will have losses due to scattering caused by surface defects. Both of these losses will depend on the optical properties of the material being used, most importantly the refractive index. Since the refractive index of the polymer material increases at shorter wavelengths towards the blue end of the visible spectrum, losses due to reflection and scattering will be greater in the blue region than in the red region of the spectrum, and the transmitted light will be yellowish. . This problem will be exacerbated by the selective absorption of blue light by the materials used to construct LCDs (including polarizers) and light guides that may be used in displays.

  One aspect of the present invention is a transmissive display device having an image output surface on which an image is displayed as an array of spaced pixel elements, where the spectral loss in the visible spectrum is the blue end of the visible spectrum. A backlight that provides illumination toward the display and a backlight that provides illumination of the display device, the light emission of the visible spectrum from the backlight being dominant at the blue end of the visible spectrum Provide type display.

  By biasing the spectrum emitted by the backlight to the blue region of the visible spectrum of light, the display device is compensated for selectively absorbing blue light, reducing the likelihood that the displayed image will turn yellow.

  Embodiments of the present invention will now be described, by way of example only, with the accompanying drawings in which:

  FIG. 1 is a schematic isometric rear view of a tiled array of display panels.

  The array has four display panels in the horizontal direction and three display panels in the vertical direction. Each display panel has a light emitting surface 10 and an image guide 20.

  The light emitting surface 10 is arranged as a large number of pixels or image elements. In practice, the light-emitting surface includes, for example, a backlight device, focusing, collimating, and homogenizing optical elements, and a liquid crystal panel or the like, but many of the above are for clarity of the diagram. , Has been omitted.

  Each of the light emitting panels displays a part of the entire image to be displayed. Part of the image represents adjacent tiles arranged in a grid pattern. However, since it is necessary to run electrical connections and physical support around the edges of the light emitting surface 10, the light emitting surface 10 directly does not leave a black band or "dark matrix" between the light emitting surfaces. Cannot be adjacent. Thus, the light guides 20 are used to increase the size of the image from each light emitting surface 10 so that the output surfaces of the light guides 20 can be adjacent to form a continuous field plane.

  The above apparatus is shown in FIG. 2, which is a schematic isometric front view of the array of FIG. Here, the output surfaces of the light guide 20 are adjacent so as to form a substantially continuous field plane 30.

  FIG. 3 is a schematic side view of a display having a light source 40, a collimator / homogenizer 50, a liquid crystal panel 60, and a light guide 70.

  The light source 40 and the homogenizer 50 are shown very schematically, but are generally arranged to provide the required backlight for the liquid crystal panel 60.

  The liquid crystal panel 60 may be of the type that provides a liquid crystal image element that uses a white or other visible colored backlight to modulate the backlight for the display. Alternatively, the liquid crystal panel 60 may be a fluorescent light emitting panel that utilizes ultraviolet light and modulates the ultraviolet light on an array of phosphors to generate visible light for the display. Of course, many other types of light emitting surfaces 10, such as organic light emitting diode arrays, may be used.

  The image guide 70 includes an array of light transmission guides 80 each transmitting light from a specific area of the liquid crystal panel 60 to a specific area corresponding to the output surface 90. In performing the above-described transmission, the light transmission guide is arranged so as to spread so that the covered area on the output surface 90 is physically larger than the image display area on the liquid crystal panel 60. As mentioned above, this allows the array of displays shown in FIG. 3 to be adjacent without an unsightly black matrix in the field plane.

  FIG. 4 shows a backlight device (light source 40) for supplying illumination to the surface of the modulator, such as the LCD panel 60 in the display, where the backlight device is arranged substantially parallel to the surface of the modulator. FIG. 2 is a schematic plan view of a backlight device that overlaps the surface of a modulator. The backlight device has a number of modules each comprising an array of light emitting structures 105 that are cylindrical. In the case of the present invention, the light emitting structure 105 is a fluorescent lamp, and may be, for example, an external electrode fluorescent lamp (EEFL), a cold cathode fluorescent lamp (CCFL), or a hot cathode fluorescent lamp (HCFL). The fluorescent lamp as described above includes a light emitting region 120, a structure for supporting the light emitting region 120 and fixing the fluorescent lamp 105 to a substrate, and a non-light emitting region including a lamp electrode to which the lamp is connected to an appropriate power source. 110.

  FIG. 4 illustrates two areas of the backlight device, area A and area B, that do not emit light. A first area A appears between the modules along the indicated y-axis. This area is of a considerable size because there are two sets of non-light emitting areas 110 of the fluorescent lamp 105 (one set consists of two modules each). The lamp electrodes in the non-light emitting area 110 of the fluorescent lamp 105 must be separated to ensure that no electrical interaction occurs between the electrodes. The second area B now appears between the modules along the x axis. However, in the case of the second area B, since the non-light emitting region 110 is absent, this area is sufficient to substantially affect the homogeneity of the light received from the backlight in the plane of the modulator. Not as big as that. Thus, the intensity delivered by the backlight to the plane of the modulator is substantially uniform along the y-axis of FIG. 4, but attenuates along the x-axis from the center toward the module edge.

  The luminance profile in the plane of the modulation surface 60 resulting from the backlight described in FIG. 4 is schematically shown by a solid line in FIG. 5A. The x-axis of FIG. 5A is parallel to the backlight device and defines a position along one axis of the modulator that is aligned with the backlight device. Thus, a given point on the x-axis of the plane of the modulator is in the exact opposite position of the same point on the x-axis of the backlight device shown in FIG. The point at x = 0 in FIG. 5A corresponds to an area of the modulator face that is exactly opposite the midpoint of area A in FIG. 4 (ie, the middle between the non-light emitting areas 110 of the two modules). .) The I (x) axis in FIG. 5A is the magnitude of the intensity of light from the backlight device that is received at the modulator plane given along the x axis. It can be seen that the intensity peak at the center of each module and the smallest indentation at x = 0, or halfway between the two modules. Thus, it can be appreciated that in order to achieve a uniform intensity across the face of the modulator, the light must be directed away from the central area of each module and toward the end of the module. The dashed line in FIG. 5A illustrates a modulator surface that corrects the intensity distribution on the modulator surface by separating the light from the strong light area and redistributing the light to the low intensity area. The effect in is illustrated.

  FIG. 5B shows an alternative of the light intensity distribution in the plane of the modulator where smaller (and more local) intensity changes can be seen over a higher frequency (ie, a frequency that does not match the module frequency). Is schematically illustrated.

  FIG. 6 is a schematic side view of one of the backlight modules of FIG. FIG. 6 illustrates a fluorescent lamp 105 and includes non-light emitting (electrode) regions 110 at both ends of the light emitting extended region 120. The light 103a emitted from the light emission extended region 120 illuminates the modulator surfaces 150a, b. If the non-light emitting area 110 and the area along the x-axis between adjacent fluorescent lamps emit light 130b, uniform illumination of the modulator faces 150a, b will be provided. Let's go. However, since no light 130b is emitted from the above areas, the illumination of the modulator faces 150a, b is not uniform, as discussed above with respect to FIGS.

  The above discussion applies in particular to the “first hit” illumination of the modulator faces 150a, b, where additional light reaches the low light flow area of the modulator face 150b by reflection inside the backlight. Please be aware of the deafness. However, although there is light redistribution within the recycle cavity, a system is introduced that selectively supports the above area and provides nearly equal brightness levels in all respects across the modulator faces 150a, b. Unless otherwise done, the overall brightness remains low over the area 150b of the modulator face.

  As an example, the intensity is uniform over 200 mm from the center of the tile, and the intensity drops linearly to 0.75 times over the outer 50 mm at both ends, i.e. the average intensity is 50 mm. Let us assume that the zone at the end of the length is 0.875 times, and the average intensity in the entire tile is about 0.96 times. Therefore, about 4% of the light flow emitted from the backlight needs to be directed to the outer zone from the center. Brightness-enhancement film (BEF) (eg, BEF manufactured by 3M) can be used to redirect light at an off-normal angle with respect to a vertical line, with a portion of the light in the outer zone The direction of the light impinging on the modulator surfaces 150a, b is relatively insignificant since the direction change can be performed by refracting the light toward the surface. However, any redirecting of light away from the central zone 150a will, of course, cause a local decrease in the light flow reaching the array of modulators in the central area 150a.

  The apparatus of the present invention recognizes that short period variations in intensity occurring in the backlight equipment can be fully compensated by the action of BEF or dual BEF film coupled to the face of the modulator. Yes.

  FIG. 7 is a schematic diagram of a backlight module similar to that shown in FIG. The backlight module of FIG. 7 is provided with a refracting surface 160 at a point selected along the length of the light emitting portion of the fluorescent lamp 105. The refracting surface 160 is arranged such that light reaching the refracting surface from the fluorescent lamp is locally redirected (along path 165) toward the dark end region of the array of modulators 150b. . The refractive surface 160 may be a Fresnel prism or a strip of lens material. They will be separated by a strip of transparent material or air. The width of the refracting surface 160, the refractive power, and the spacing between the refracting surfaces can be changed depending on the luminance profile of the backlight that is not changed, and the display device in which the backlight and the modulator are mounted. Results in periodic changes in intensity, wavelength, and amplitude that are small enough to produce a visually uniform output. This prevents the “window pane” effect of the uncorrected output from the backlight.

  FIG. 8 is a schematic diagram of an alternative backlight. In this device, a diffusive reflector 170 is used instead of the refracting surface 160 (possibly associated with the refracting surface 160), and the modulator surface has a high to low region 150b. Turn the light into the direction. In particular, a portion of the light emitted from the light emitting region 120 of the fluorescent lamp 105 strikes the reflective surface 170 and is redirected (along the path 175) back toward the fluorescent lamp and the substrate, again, the modulator surface 150a. , B (especially toward 150b, which is a low luminance region), the light is reflected.

  FIG. 9 is a schematic diagram of an alternative backlight. In this device, a specular or diffusive reflective surface 180 was provided on a plane substantially perpendicular to the plane of the backlight in the non-light emitting area of the backlight and would have received low levels of illumination. Light that does not impinge on the modulator face is selectively redirected toward the planar end 150b. This diffusive reflective surface may have a strip of material, but would normally direct light going to the “dead” space between the displays towards the active area of the display surface, especially at low levels of illumination. Reflect towards the area that was supposed to receive. In general air cooling systems where air flow is required between the fluorescent lamp and the modulator array, the reflective surface 180 cannot be continuous between the backlight substrate and the modulator surface 180. . Otherwise, the air flow will be obstructed.

  FIG. 10A is a schematic diagram of a backlight that operates in the same manner as described above but does not obstruct air flow to some extent. In this device, specular or diffusive reflective surface 190 reflects a significant portion of the light from the lamp along path 195 in a manner similar to the device of FIG. 9, while allowing air to flow. It is installed on the armor door structure. This structure can be formed by, for example, expanded metal. This device is very well suited for displays where the space between the backlight and the modulator needs to be cooled for forced air circulation or for convenience. This is because the diffusion strip has less resistance to air flow than the structure without gaps shown in FIG. FIG. 10B is a schematic diagram of an incoming air stream 197 that passes through the diffusion strip 190 to produce an air stream 198. The incoming air flow 197 may be split and redirected, but it can be seen that the flow path is not substantially disturbed.

  The various structures 160, 170, 180, 190 that redirect light can be used in various combinations to create an improved illumination pattern in the plane of the modulator. All the backlight devices described above operate on the principle of redirecting light to homogenize the illumination of the modulator face. This is particularly recommended in backlight devices where uniform illumination of the modulator surface is achieved by selectively absorbing light emitted from the fluorescent lamp. For example, in the example of FIG. 6, the overall brightness of the backlight needs to be reduced (through the light absorbing structure) by 75% (which is the intensity at the edge of the modulator surface 150b); There is a 25% reduction in display brightness and a similar reduction in output efficiency. In contrast, the reflection technique used in the above-mentioned device is virtually lossless and, based on the above example, only a 4% reduction in brightness peak, and an average There is no decrease in the brightness of the.

  FIG. 11 is a schematic diagram of a connecting device of the LCD panel 210 to the image guide 220. It can be seen that the image guide is surrounded by a frame 230, hereinafter referred to as the base frame 230. The base frame 230 is preferably made of a material having a thermal expansion coefficient close to that of the image guide 220. The base frame 230 may be coupled to the image guide 220 by any suitable means such as bonding. As shown in FIG. 11, the input surface of the image guide 220 extends slightly beyond the input surface of the base frame 230 (the closest surface parallel to the input surface of the image frame 220) (eg, 100 to 500 microns). M) It is preferable that it protrudes.

  A first frame 240 made of a material having a coefficient of thermal expansion substantially the same as the coefficient of thermal expansion of the base frame 230 is firmly coupled to the input surface of the base frame 230. The first frame 240 may be accurately positioned with respect to the image guide by physical means such as two dowels inserted into the frame 230. Each of the two dowels may be positioned within a snug hole in the image guide and a snug slot. The first frame 240 includes an opening exposing the input surface of the image guide and a part of the base frame 230. The LCD display fits the opening provided by the first frame 240 with some free space provided around the edge of the LCD as a allowance for different expansions between the LCD and the frame. It is also foreseen that the base frame and the first frame may be formed together as a single structure.

  The second frame 260, which is preferably composed of a material having a thermal expansion coefficient similar to that of the first frame 240, is a polymer foam having a low modulus of elasticity (as manufactured by 3M Company), for example. The first frame 240 is joined so as to be flexible through an intermediate layer having a low elastic modulus, such as a double-sided tape layer. The second frame 260 also has a smaller opening than that of the first frame 240 and overlaps the edge of the LCD panel 210. The second frame is preferably made of a thin material, for example 50% thicker of the LCD panel, and is therefore rigid in a plane parallel to the LCD but perpendicular to the plane of the LCD. Is harder than the LCD or the first frame. The layer of foam tape preferably covers substantially all of the bottom surface of the second frame 260 and bonds the second frame 260 and the LCD panel 210 together. Therefore, there is no hard connection between the LCD and the second frame 260. The apparatus is arranged such that the second frame is distorted in a direction perpendicular to the plane of the LCD panel and away from the plane of the LCD panel. This distortion causes a force applied to the LCD panel 210 by the second frame 260 in the direction of the image guide. The force required to distort the second frame 260 is insufficient to cause any significant distortion in the LCD panel 210.

  The LCD panel 210 is in contact with the input surface of the image guide 220 as a result of the force applied to the LCD panel 210 by the second frame 260 (force acting in the direction of “pressing” the LCD panel 210 with respect to the image guide 220). And preferably also by a method of bulging the image guide 220 beyond the plane of the base frame 230.

  12A-12C are schematic diagrams of the various “layers” that the apparatus described in FIG. 11 comprises.

  FIG. 12A is a schematic diagram of the existence range of the image guide 220, the base frame 230 surrounding the image guide 220, and the LCD panel 210 placed with respect to the image guide 220 and the base frame surrounding the image guide 220. The broken line schematically illustrates the existence range of the image area 215 of the LCD panel. In this example, the image area does not cover the entire area of the LCD panel, and due to the configuration of the LCD, there is a noticeable asymmetry in the position of the image area 215.

  FIG. 12B is a schematic diagram of the positioning of the first frame with respect to the image guide 220, the base frame 230, and the LCD panel 210. It can be seen that the first frame is positioned with respect to the base frame 230 and surrounds the outer periphery of the LCD panel 210 but does not overlap the LCD panel 210.

  FIG. 12C is a schematic view of the positioning of the second frame with respect to the image guide 220, the base frame 230, the LCD panel 210, and the first frame 240. It can be seen that the second frame is positioned with respect to the first frame 240 and overlaps the outer periphery of the LCD panel 210. It is this overlap that helps to hold the LCD panel 210 against the image guide 220. The second frame 260 will not overlap the image area of the LCD panel 210.

  In the embodiment of FIG. 12, each of the first frame 240 and the second frame 260 is comprised of four separate strips. The joint between the separated strips of the first frame 240 does not coincide with the joint of the separated strips of the second frame 260. This is because when the two frames are bonded to each other by the adhesive layer 250, the two frames are bonded to each other as one unit.

  Instead, either one of the first frame 240 and the second frame 260, or each is positioned at a continuous frame or at various points on the periphery of the LCD panel (eg, corners of the LCD panel), You may have a set of non-adjacent elements.

As described above with respect to FIG. 11, the first frame 240 and the second frame 260 are preferably bonded together with a layer of low-modulus double-sided polymer foam tape 250, Also, the second frame is coupled to the LCD panel in a flexible manner. This flexible coupling allows relative movement between the first frame 240, the second frame 260 and the LCD panel 210 under conditions of thermal expansion. In particular, when the temperature changes, the first frame 240 and the image guide 220 (the image guide frame 230) expand by a larger amount than the LCD panel 210 expands or contacts. And touch each other. This different expansion creates a shear stress in the low modulus polymer foam tape 250 that bonds the first frame 240 to the second frame 260 and the second frame to the LCD panel 210. Due to the low elastic modulus of the tape 250, this shear stress is low and the LCD panel will be slightly distorted or not distorted. Due to the arrangement of the array dwells, the different movements between the LCD and the image guide are symmetric with respect to the center point of the LCD, thus minimizing the magnitude of the alignment error between the LCD and the image guide. .

  In accordance with the above, it is desirable to maintain the LCD panel 210 so that it is closely aligned and in close proximity to the image guides that are not inflatable.

An exemplary method for coupling the LCD panel 210 to the image guide 220 is as follows.
(1) The LCD panel 210 is arranged on the base frame 230 of the image guide 220 with respect to a point on the opposite side of the diagonal line, and is tightened to a plane by, for example, drawing a vacuum.
(2) The first frame 240 is arranged on the base frame 230 by a method of two dwells at the same position as the dwell of the base frame 230.
(3) The release layer is removed from the exposed surface of the foam tape 250, exposing the underlying adhesive, and the second frame 260 is lowered onto the first frame 240, and through the adhesive, each other It will be in the state where it adhered to. The adhesive also bonds the second frame to the LCD panel and ties the first frame 240, the second frame 260, and the LCD panel 210 together.
(4) The first frame is firmly attached to the base frame 230 (and therefore the image guide 220) by means of screws. In this embodiment, the screw penetrates the second frame 260 but does not exert a force in any direction.

  Any suitable alternative method that constitutes a combination of an LCD panel and an image guide can also be used.

  The base frame 230, the first frame 240, and the foam tape 250 are preferably opaque. The second frame 260 may be opaque and ideally should be diffusely reflective (eg, white) on the side where the foam tape 250 is not adhered. This recommended feature reduces the risk of light leaking around the frame by returning light incident on the frame into the backlight cavity and improves the efficiency of the backlight system.

  13 and 14 are a schematic plan view and side view, respectively, of an array of light transmissive guides. As shown in FIGS. 13 and 14, each light transmission guide 380 is on an individual pixel element, but there are devices with a large number of pixel elements per light transmission guide 380 or a large number of light transmissions per pixel element. Other devices such as those with guides 380 are of course possible. The light transmission guide 380 is separated by a groove 300 that is preferably filled with a low refractive index adhesive. It can be seen that the array of light transmissive guides 380 that together constitute an image guide is surrounded by a frame 310 coupled to the array of light transmissive guides 380 by suitable means, such as gluing.

  In normal operation, a certain amount of light may propagate from one light transmission guide 380 to an adjacent light transmission guide. This is in particular due to one or both of the following two features: First, some light propagates at a large angle with respect to the wall of the light transmissive guide and exceeds the critical angle for total internal reflection at the boundary between the light transmissive guide 380 and the adhesive filling the groove 300. And may be transmitted to adjacent fibers. Second, some light may be incident on the fiber adjacent to the intended fiber due to the finite gap that exists between the input end of the light transmission guide 380 and the image output surface 380. . Such behavior is undesirable but difficult to control.

  The means that the frame 310 is attached to the outermost light transmission guide of the image guide 20 in order to reduce the luminance variation between the central area and the peripheral area of the image guide The goal is to keep the optical properties that exist between the fibers that are not there constant. An example device that addresses this problem is illustrated in FIGS. 15A and 15B. The frame 310 has both an outer frame 311 and an inner frame 213 made of a material having optical characteristics similar to those of the light transmission guide, and is optically substantially the same as the method in which the light transmission guide 380 is attached to each other. The method is connected to a peripheral light transmission guide (ie, a light transmission guide adjacent to the frame). The inner frame 312 is sandwiched between the outer row of the light transmission guides 380 and the outer frame 311 (which gives the structure rigidity). Inner frame 312 may, for example, take the form of a continuous boundary of material surrounding all faces of the array, or it may have an additional boundary of light transmissive guides 313 surrounding the array. . The additional boundary of the light transmissive guide 380 may be the thickness of the single light transmissive guide 380 or may be arranged as a row of light transmissive guides 380 along each edge of the inner frame 312. It may be the thickness of the light transmission guides 380 in rows or more. In the former, the continuous boundary of material will not extend to the plane of the output end of the light transmissive guide. In the latter case, the additional light transmission guide will be cut off so that it does not reach the plane of the output end of the light transmission guide. The outer frame 311 may have the same, similar, or different optical characteristics as the light transmission guide 380. The preferred arrangement of the outer frame 311 supports the array of light transmissive guides 380 and prevents the light transmissive guides from being misplaced with respect to the underlying pixel elements of the display device 60, Can connect to placement on tiles.

  Light entering the inner frame 312 is prevented and at least suppressed from exiting the inner frame 312 in such a way as to degrade the visual characteristics of the display.

  FIG. 16 is a schematic view of a mechanism for preventing or suppressing light from being emitted from the inner frame. Where the inner frame 312 has a light transmissive guide that is cut at the tip, these have an upper cut end (eg, coated) covered with a light absorbing layer 314, and the inner frame 312. Where there is a continuous boundary of material, the end of the light transmissive guide farthest from the input surface is covered (eg, coated) with a light absorbing layer 314. In either case, the light absorbing layer 314 substantially prevents the propagation of light beyond the end of the inner frame.

  The optical path followed by the light entering the inner frame 312 in the absence of the outer frame 311 is shown in FIG. 16 by the approximate rays 331, 332, 333, 334. The light beam 331 enters the inner frame 312 through a joint between the inner frame 312 and the adjacent light transmission guide 380. The approximate light ray 331 is reflected internally by the inner frame 312 and finally absorbed by the light absorption layer 314.

  The light beam 332 hits the input surface of the image guide at a smaller angle than the light beam 331 and does not enter the inner frame 312.

  The light beam 333 enters the inner frame 312 through the input end of the inner frame 312, is reflected inside, exits the inner frame 312 through the coupling between the inner frame 312 and the adjacent light transmission guide 380, and is adjacent to the inner frame 312. The light passes through the light transmission guide 380 and further passes through another light transmission guide 380.

  The light beam 334 also enters the inner frame 312 through the input end of the inner frame 312, is internally reflected by the inner frame 312, and is finally absorbed by the light absorption layer 314.

  FIG. 17 is a schematic diagram of the operation mechanism of FIG. 16 when fixed to the outer frame 311. The optical path followed by the light entering the inner frame 312 when the inner frame 312 is fixed to the outer frame 311 is illustrated in FIG. 17 by the approximate rays 331 ', 332', 333 ', 334'.

  All approximate rays 331 ′, 333 ′, and 334 ′ that strike a portion of the inner frame 312 that contacts the outer frame 311 are absorbed on the interface between the inner frame 312 and the outer frame 311. The light beam 332 ′ does not hit this boundary surface and is not affected by the presence of the outer frame 311.

  As described above, the outer frame 311 is preferably made of a structurally strong material and absorbs light for reasons of system optical efficiency. A preferred method of attaching the inner frame 312 and the outer frame 311 to each other is a means called an adhesive layer 315. However, as can be seen from FIG. 17, when the outer frame 311 is attached, less light is propagated by the inner frame 312.

  FIG. 18 is a schematic diagram of an alternative apparatus that seeks to overcome the above disadvantages. Comparing FIGS. 17 and 18, the light blocking layer 314 has been removed and replaced with a reflective layer 316. The reflective layer covers substantially all surfaces of the inner frame 312 except for the input surface and the portion of the inner frame 312 that is in contact with the adhesive layer that couples the inner frame 312 to the adjacent light transmission guide 380. The improvement in optical efficiency is that the approximate ray 333 "does not follow the same path as in FIG. 16, but the approximate rays 331" and 334 "are reflected several times and the inner frame 312 or the adjacent light transmission guide 380 is reflected. It can be seen that it will reappear from the entry surface and potentially be reused to improve the luminous efficiency of the system.

  Another advantage of this device is that the properties of the outer frame 311 and the adhesive used to bond the outer frame 311 to the inner frame 312 can be made completely independent of the optical properties of the device. It is.

  The reflective layer 316 may be disposed on the inner frame 312 as a metal layer, or may be applied in the form of a metal adhesive.

  FIG. 19 is a schematic view of one image guide with a surrounding base frame 410. Each of the image guides 470 in the array on the tile is machined or made of a suitable material (such as a polymer) selected for stiffness, strength, low friction, and a coefficient of thermal expansion that matches the coefficient of thermal expansion of the image guide 470. It is glued into the cast rectangular support frame 410.

The reference outer dimension of the base frame 410 is preferably substantially the same as the dimension of the output end (front face) of the image guide 470. Since the thermal expansion coefficients of these components are substantially equal, the outer dimensions of the base frame 410 and the front of the display remain nominally the same in the temperature range in which the display operates.

  The individual image guides 470 are glued to the individual base frame 410 by specially configured jigs so that the individual image guides 470 can be accurately assembled prior to final assembly of the complete tiled display. This ensures the correct alignment of the base frame 410 with respect to the image guide 470.

  FIG. 20 is a schematic view of an array on an image guide tile held together by a support structure frame. In the above tiled apparatus, the individual image guides are tiled in a rectangular array, along with the flat strips 420 and other adjacent modules held together by the method of connecting adjacent modules to each other. Be placed. The change in dimensions between the strip 420 and the corresponding mounting point on the base frame 410 is small at the distance involved and therefore the pressure imposed by the difference in thermal expansion in this small area is not significant, so the strip 420 may optionally be composed of metal.

  Base frame 410 provides rigidity and maintains an array of light transmissive guides 380 in a plane parallel to the display front. To prevent relative movement perpendicular to the front, the array of base frames 410 is reinforced by a support frame 415 (which may be metal or have reinforced plastic). The support frame 415 has both horizontal struts 495 as shown in FIG. 20 and vertical struts 430 as shown in FIG. 21 (described below).

  FIG. 21 is a schematic cutaway view of the intersection between the base frames 410 of the two image guides 470. The vertical struts 430 of the support frame are preferably located in the groove between the base frame and two adjacent image guides 470, but the vertical struts 430 are instead completely within the base frame 410. Alternatively, it may be partially buried.

  The support frame 415 may be composed of extruded aluminum, for example, for low budget, light weight, and ease of processing.

  The base frame 410 is preferably attached to a support frame 415 that uses the structure illustrated in FIG. Base frame 410 is spring mounted on vertical support struts 430 using, for example, a crinkle washer (or other spring mounted device) held between large diameter washers 480, 490. . The screw 450 is fully tightened to the hollow spacer 460 to deflect the crinkle washer by a predetermined amount. The resulting force on the base frame 410 is sufficient to keep the base frame in contact with the metal structure frame 415, but the temperature changes so that the polymer expands and contacts the support frame 415 relatively. Horizontal movement is allowed. A large clearance hole 425 is provided in the base frame 410 to provide space for relative movement in a plane parallel to the front area.

  The low friction property of the base frame 410 ensures that the pressure on the polymer portion of the system is at a low level when the screen expands and contacts the support frame 415 relatively.

  As the temperature changes, the array of image guides with the base frame expands and contacts each other by a greater amount than the support frame expands and contacts.

  FIG. 22 is a schematic diagram of a system for increasing contrast. In an LCD based display, the amount of light exiting the LCD 510 is controlled by adjusting the polarization. This means that the output light (for all gray levels) will have the same defined polarization. On the other hand, ambient light will not be polarized. Rather than coupling ambient light traveling from the input of the image guide 570 toward the LCD 510 to the output polarizer 520 of the LCD, a polarizer 530 is attached directly to the input array of the image guide 570. As a result, the ambient light is directly coupled to the polarizing plate 530 and approximately 50% of the ambient light is absorbed. Most of the remaining ambient light exits the polarizers 530 and 520, hits the LCD 510, is absorbed (when the image on the LCD is black), and (when the image on the LCD is white) ) Transmit the backlight.

  FIG. 22 shows that ideally linearly polarized light exits the LCD polarization modulators 510, 520 and is incident on the idealized polarizing plate 530 where 95% is transmitted (5 % Is reflected by Fresnel reflection).

  Undesirable ambient light reaching from the other direction passes through the same polarizer 530 in the opposite direction. Since the light is not polarized, substantially half of the ambient light is absorbed by the polarizing plate 530. Of the remaining half, approximately 47.5% is transmitted and approximately 2.5% is reflected at the boundary between the polarizer and air, contributing to the backscattered light seen by the viewer.

In reality, the polarizing plate 530 does not transmit 50% of the ambient light and does not transmit 95% of the light from the LCD 510. Transmittance is a standard equation for non-ideal polarizer transmittance,
(Formula 1) T = K1 cos ² θ + K2 sin ² θ
Follow.
Here, K1 is the transmittance of linearly polarized light parallel to the transmission axis of the polarizing plate, K2 is the transmittance of linearly polarized light perpendicular to the transmission axis of the polarizing plate, and θ is It is an angle between the polarization axis of incident light and the transmission axis of the polarizing plate, and T is a transmission coefficient. As a practical example of K1 and K2, in a commercially available HN-38 Polaroid (RTM) polarizer (at 550 nm), K1 and K2 are 0.74 and 4 × 10 ⁻⁵ , respectively. In terms used by Polaroid, H indicates a polarizing plate made from iodine fixed to stretched polyvinyl alcohol, N indicates achromatic to the layer, and the number 38 is unpolarized. The approximate value of the transmittance | permeability in percentage display of one polarizing plate with respect to white light is shown. Other polarizing plates with higher transmittance can also be used.

FIG. 23 shows a similar, but simpler, polarizing plate 530 disposed at the input of the image guide 570 is aligned with the transmitted polarized light of the LCD device 510, with no polarizing plate provided on the output surface of the LCD 510. FIG. This polarizing plate 530 will have the same effect in terms of the polarization-modulated LCD, but is coupled to the image guide 570 (if it reflects ambient light back towards the viewer) N) Couple ambient light to the polarizer described above. This device has the additional advantage of increasing the flow rate while maintaining the same ambient light absorption. In this case, the polarizing plate 530 replaces the output polarizing plate of the LCD. The advantage of placing the polarizing plate on the input surface of the image guide is that, as described above, the refractive index of the adhesive is improved compared with the case where the polarizing plate is attached to the LCD. So) ambient light is efficiently coupled to the polarizer. Regarding the efficiency of the LCD, whether the polarizing plate is attached to the LCD or the image guide 570, it is substantially the same when the light path involves two boundaries of solid and air. is there.

  FIG. 24 is a schematic view of an apparatus similar to FIG. 22 but with a phase modulation layer 540 coupled to the image guide polarizer 530. Even when the above-described polarizer arrangement is used, a part of the light that is not absorbed is reflected at the boundary between the polarizing plate at the input end of the image guide 570 and air, and is returned to the image guide 570 through the modulator 530. This light reaches the viewer and adversely affects the contrast. If the proportion of ambient light transmitted towards the viewer in this way is unacceptable, additional components can be added in the form of a phase modulation layer 540. The phase modulation layer 540 is transmitted through the image guide input polarizing plate 530 and the LCD polarizing layer 520, and the polarized light that is reflected back toward the image guide input polarizing plate (at this stage) is elliptically polarized. And thus arranged to be partially absorbed for some time while traversing the image guide 530. For reflected light, phase modulation occurs in either direction through the phase modulation layer 540 and light from the LCD polarization modulation layer traverses the phase modulation layer 540 only once. The phase modulation layer is chosen to reduce the change in polarization of the LCD light (thus minimizing absorption). This decrease in change is balanced against a corresponding increase in reflected light absorption.

  In the most extreme case, the phase modulation layer 540 rotates the polarization of linearly polarized light by 45 degrees in each pass through the layer. This means that ambient light reflected at the polarizer-air boundary is rotated 90 ° (in two strokes) and substantially all is absorbed by the image guide input polarizer 530. To do. On the other hand, the light from the LCD is rotated only 45 °, and half of the light is absorbed by the input polarizing plate 530 of the image guide. Because of the severity of the above penalty for brightness loss, a smaller phase lag may be used in each path through the phase modulation layer 540 that converts linearly polarized light into slightly elliptically polarized light, Thereby, a smaller part of the LCD light is absorbed, ensuring that a larger part of the ambient light reflected at the boundary (because it passes twice through the delay) is absorbed. Therefore, it is necessary to balance the brightness and efficiency of display devices that require high contrast.

As can be inferred from (Formula 1), the alignment of the polarizing plates is required to have a small tolerance. The main part of (Equation 1) is the term of K1 cos ² θ. If the arrangement is shifted 6 degrees, this term becomes approximately 0.989K1.

  FIG. 25 is a plot of normalized measurements of transmission through a third polarizer placed in front of a 15 inch display and rotated at a range of angles. This plot shows the magnitude of the transmission through the third polarizer as a function of rotation angle. The orientation is initially chosen at random, and then stepwise rotated to a range of angles greater than 90 degrees.

  Alternative, more complex devices that require more than one delay layer are possible. From the two devices, in order to improve the transmittance of the LCD light, a second phase modulation layer is introduced at the output of the LCD to offset the effect of the input phase modulation layer 540 of the image guide. That is, the phase modulation layer at the output of the LCD converts light into right-handed elliptical (or circular) polarized light. This light is then converted back to linearly polarized light and transmitted as it passes through a phase modulation layer 540 optically connected to the input polarizer 530 of the image guide. Ambient light transmitted through the polarizing plate 530 of the image guide is converted into right-handed elliptically polarized light when passing through the phase modulation layer 540 of the image guide. However, at the reflection at the phase modulator layer-air boundary, any light returned through the phase modulator becomes left-handed elliptically polarized light and is converted to an orthogonal linearly polarized state. . This device operates in the same way as in the previous example, but with almost no loss of light transmission from the LCD. For example, assuming that the phase modulation layer on the LCD provides quarter-wave circular or elliptical polarization, the circularly polarized light is transmitted to the phase modulation layer on the image guide. If this light is directed at 90 ° with respect to the phase modulation layer on the LCD but otherwise identical, the circularly polarized light is converted linearly by the polarizer on the image guide. It will be turned back and substantially 100% will be transmitted. Ambient light is transmitted as circularly polarized light in the groove between the image guide and the LCD, and has a handedness (eg, left-handed system) in reflection from the boundary between the LCD phase modulator layer and air. From right to right). On passing through the phase modulation layer of the image guide, the light will be returned to the linear polarization state rotated 90 ° from the initial state and will therefore be prevented by the polarizer.

  In general, any combination of polarizers and phase modulation layers (including cholesteric polarizers) in an arrangement within an image guide system will produce the desired result.

  In addition to the above devices, the system can also include an anti-reflective (AR) coating that increases the flow rate from the LCD modulation layer and at the boundary between the new component of this image guide input and air. Reduce the proportion of ambient light that is reflected.

  Thus, it can be seen that a method has been provided in which ambient light can be suppressed by using an additional polarizer coupled to the input surface of the image guide. Ambient light guided to this plane will be lost due to its unpolarized nature and the transmission nature of the polarizer.

  The above principle is not limited to use for displays based on image guides, for example, displays with simple glass or plastic sheets (with AR coating), (eg touch panels) In addition to the image guide, it has general applications such as the above-mentioned display used for touch and application to sound (for example, a transparent sheet used for a loudspeaker device). The concept is not limited to simply improving the contrast of a tiled LC display.

  For example, in applying this concept to a single high contrast LCD system, the devices described above are equally applicable, and other devices are also possible.

  FIG. 26 is a schematic diagram of a contrast enhancing device provided in one high contrast LCD system. A glass sheet 580 with an anti-reflective (AR) coating is provided with a polarizing plate 590 on the opposite side of the AR coating, the polarizing side of the glass sheet 580 being polarized on both the input and output surfaces. Facing the LCD layer 510 ′ with the plates 520 ′, 521. Providing a polarizer 590 on the side of the AR-coated glass 580 that faces the LCD 510 ′ helps couple the received ambient light to the polarizer 590.

  FIG. 27 is a schematic diagram of another apparatus for enhancing contrast provided in a single high contrast LCD system. 26 is similar to the apparatus of FIG. 26 in that the AR coated glass sheet 580 described above is provided with a polarizing plate 590 on the opposite side of the coating. However, on the opposite side of the AR-coated glass sheet, in addition, only a small percentage of ambient light passing through the polarizer 590 is reflected back from the polarizer-air boundary towards the viewer. A polarizing plate 590 is provided together with the AR coating 595.

  FIG. 28 schematically compares the general principles of the above apparatus using a neutral filter (or a protective window on the front of a standard LCD) to reduce environmental reflections from the image guide input surface. It is a thing. As shown in FIG. 28, when a polarizing plate is introduced on a simple optical flat element, the Fresnel reflection of ambient light from the back surface is roughly halved from 0.04 to 0.02. When ambient light is incident on the output of the image guide, this value includes the case of Fresnel reflection in front of the image guide.

In order to replace a polarizer with a neutral filter that performs a similar reduction in the level of ambient light reflected back to the viewer, the amount of light that passes through the two paths through the filter is determined by the optical plane. Must be equal to half the amount of light that is reflected and absorbed from the back. This is expressed by the following equation.
(E ^−αx ) ² = 0.5
Where α is the optical density coefficient (per path length) and x is the path length through the neutral filter.

If this partial transmission is relative to the amount of light passing through the two paths through the filter, the neutral filter's single path absorption must be approximately (0.5) ^0.5 = 0.7071. It will not be.

  Considering the light leaving the modulator (towards the viewer), you can see the advantages of the system proposed above. In particular, the polarizing plate receives light polarized parallel to the transmission axis of the polarizing plate and transmits 96% or more (ignoring Fresnel reflection), while the neutral filter transmits only 71% or less of the light. . The neutral filter situation worsens as more absorption from the filter is sought due to the negative effect on the achievable contrast due to the reduction in image brightness.

  Therefore, there is no need to apply a non-reflective coating to the input of the image guide or the output of the LCD while maintaining a high transmittance from the backlight, and an inexpensive method for reducing the proportion of reflected ambient light is provided. . The advantage of this is that contrast is improved by using relatively thin and cheap components that allow the array of image guides to be located close to the modulation layer of the LCD (or other polarization modulator). including.

  FIG. 29 is a schematic view of a display screen having an image guide 20 and having a conventional transparent electrically conductive layer 620 that covers the viewing surface 90 and an electrically conductive shield 610 that forms an enclosure around the screen electronics. . Electromagnetic waves emitted from the screen electronic device (for example, the driving electronic device of the LCD modulator 60) are an electrically conductive shield 610 provided around the display device, and a transparent attached to the front surface of the display and coupled to the electrically conductive shield 610. Due to the presence of the electrically conductive layer 620, it is not allowed to leave the display vicinity.

FIG. 30 is a schematic diagram of an advantageous shielding device applicable to a display having an image guide 20 provided between a display panel or modulator 60 and an image output surface 90.
In order to prevent electromagnetic waves from propagating through the image guide 20 toward the image output surface 90, an electrically conductive material is provided in a gap between the light transmission guides 80 constituting the image guide 20. . One possible means is to use a carbon-filled plastic strip that also serves to reduce light leakage and interference between the light transmissive guides 80 of the image guide 20. Alternatively, a thin metal wire or some other electrically conductive layer applied between the light transmissive guides 80 but not substantially in optical contact with the light transmissive guides 80 can be used.

  Such a device advantageously provides better optical efficiency for similar displays in general having an electrically conductive layer covering the viewing surface. This is because the electrically conductive layer may absorb a portion of the light that is about to exit the display, while the strip of material 640 provided between the light transmissive guides 80 allows light to exit the display. This is because it absorbs only undesired light (interference between the light transmission guides 80).

  Using a transparent electrically conductive layer provided across the viewing area of the display is an optical artifact that occurs at the junction between the conductive layers of a tiled display (with the conductive layer applied to the outside of the screen) Tend to cause. Shielding devices that do not use a transparent conductive layer across the field of view of the screen will not cause this optical artifact. Furthermore, the device couples the modulator 60 to the input of the image guide better than in the case of a display with a conductive layer applied to the output face of the modulator 60. The device also saves considerable costs.

  As can be seen from the cutaway view of FIG. 30, the carbon-filled polymer strips 640, as explained above, are mainly arranged in the rows and columns of light guides during the manufacturing process to improve optical efficiency. It may be placed between either or both. When the polymer strips 640 are bonded to each other and to the outer frame of the display, the active elements on the front of the display are shielded and substantially reduce electromagnetic radiation. The electrical conductivity of the black polymer strip 640 is very low. Therefore, to improve the electrical efficiency of the above-mentioned devices, use high-quality, high-conductivity wires (for example, made of copper, aluminum, or silver, for example, 0.25 to 0.1 mm in diameter) The wire itself (preferably knitted on a mesh) can be used, or it can be used electrically coupled to a strip 640 of conductive polymer.

  Problems may arise with tiled arrays of display panels that use a progressive scan addressing scheme to drive each panel (eg, LCD panel) in the array. When this method is used, the entire image on the panel is not refreshed at the same time during one frame, but starts at the top row of the panel at the beginning of the frame and at the bottom row of the panel at the end of the frame. end with. Conventionally, it typically starts refreshing the top row of the display and works downwards. This means that in a tiled array of panels, the top row of one panel is refreshed at the beginning of a frame, while the bottom row of panels just above the panel keeps the image from the previous frame. It remains. This remains until the end of the frame where the bottom row is finally refreshed. However, just after this, the top row of the lower panel is refreshed with the information of the next frame, so again the top row of one panel and the bottom row of the (adjacent) directly above panel. There will be a single frame mismatch between them. This in itself is not a problem for still images where the information of successive frames is substantially the same, but is a problem for moving images, especially for fast moving images where the consecutive frames are significantly different. Appears as a break. This phenomenon is an undesirable motion artifact.

  The above behavior is illustrated in FIG. As shown in FIG. 31, on the left side of the diagram, a static line 701 is shown consistently across the tile boundary 705, and on the right side of the diagram (as indicated by arrow 707). A flow line 702 (moving in the indicated direction) is shown to be discontinuous when crossing a tile boundary 705. This effect is particularly noticeable in tiled displays that are substantially “seamless”. This is because seams distract from the discontinuities that are now a problem.

  FIG. 32 shows an inverted image of panel rows 730 in a tiled array rotated every other row by 180 degrees, resulting in a 'right-facing' final image. FIG. 2 is a schematic diagram of a tiled display device that hides motion artifacts by providing information. In the plane of the panel 730, by rotating the panel 730 every other row by 180 degrees, the top row 720 of one display panel is refreshed simultaneously with the bottom row 725 of the display panel 730 directly above, Be sure. The display panel 730 scans in the normal way, but the lines on the boundary of the two panels are always updated simultaneously on both panels. In an alternative device that provides a similar effect, the pixel addressing scheme is changed every other row to scan from bottom to top rather than from top to bottom rather than rotating the panel every other row.

  As shown in FIG. 32, both the second and third columns of the panel begin to refresh the lines (shown by lines 720, 725) adjacent to the border where they touch each other at the beginning of the frame. Heading to the end of the frame (scanning direction indicated by arrow 710), each of columns 2 and 3 refreshes the line adjacent to the boundary between the respective adjacent columns (column 1 and column 2). The Column 1 and Column 2 panels are also refreshing the lines adjacent to the boundary at the same time, so no discontinuity is noticeable.

  This alleviates the current problem of discontinuities at the tile boundaries, but is not directly applicable to any tiled display product. In conventional LCD panels, the brightness (and contrast) of the display varies with the viewing angle. Furthermore, this change may not be symmetric with respect to the normal of the display surface. This means that in traditional (eg twisted nematic LCD) tiled displays, there may be a visible difference in efficiency between a 'right-orientated' panel and a 'upside down' panel. Means.

  If the viewing efficiency of each panel can be angularly symmetric with respect to the normal of the display surface, the above solution can be implemented without visible side effects.

  FIG. 33 is a schematic diagram of the magnitude of the asymmetry of the angle between the image guide and the LCD panel. In particular, FIG. 33 illustrates the contrast ratio exhibited by the image guide and the LCD panel as a function of viewing angle. Both the LCD panel and the image guide typically show the same rate of contrast ratio, whether upside down or not. However, for example, if the viewing angle deviates from normal by 5 degrees, a correctly oriented LCD panel will show a contrast of about 200: 1, while an adjacent upside down LCD will show a contrast close to 100: 1. This means a 2: 1 contrast in brightness between panels. Image guides, on the other hand, have a more symmetric efficiency and the contrast in the positive direction is very close to the contrast in the negative direction, so in a display that uses an image guide, every other row has a panel at every viewing angle. It is not important for viewers to be upside down.

  Other methods of hiding and removing the motion artifacts described above can cause image processing of each image frame (temporal interpolation) and delay of one frame time between each column of the panel. Including. The latter method may include, for example, starting frame 1 in the third row when the top row of the tiled display starts frame 3. This satisfies avoiding discontinuities at the boundaries between columns without turning the LCD panel upside down, but creates a visible 'tilt' of the image as it moves, It causes lip sync problems in the display's sound system. This is because the lower row displays an image that was displayed a few frames (possibly hundreds of milliseconds on a large display) at the top row. In addition, in order to change the refresh pattern of the display panel, the driving method of the display panel is changed.

  FIG. 34 shows how the color where the spectral attenuation of the light going from the backlight to the field of view and passing through the display is the “white point” of the display is now recognized as white by the viewer. It shows schematically whether it shifts to the limit which cannot be done. The “white point” is a color value (for example, red, green, blue (RGB) value or Kelvin display color temperature) defined as white in a color display. The white point is usually composed of the maximum value of each color component (for example, RGB) used in the display. The white point of the display can be defined and plotted, for example, on a chromaticity diagram using the CIE 1931 standard. It is this standard that is used in FIG.

  The CIE 1931 standard represents a range of light that can be recognized by the human eye using a luminance parameter and two chromaticity parameters x and y. The x and y axis parameters form part of a triaxial representation that also includes the parameter z. However, in the CIE 1931 standard, x + y + z = 1 and the value of z is known to be given the values of x and y, and therefore gives no additional information. Therefore, a two-dimensional display is sufficient to represent chromaticity.

  Curve 880 plotted in FIG. 34 represents the range of spectral colors (ie, light composed of a single wavelength), with wavelengths in nanometers (nm) plotted at discrete points along curve 880. Yes. A given point inside curve 880 represents light with mixed wavelengths. All of the points outside the area defined by curve 880 relate to light that is not perceivable by the human eye.

  As shown in FIG. 34, the “white point” of the light emitted from the backlight is indicated by a plot point BL of coordinates (0.295, 0.310). The white point of this light after passing through the sample LC display panel is indicated by the plot point BLLC at coordinates (0.309, 0.345). This is a significant spectral shift at the position of the white point. The white point of light after passing through both the LC display panel and the sample image guide is indicated by the plot point BLLCIG at coordinates (0.328, 0.369). Again, this is a significant spectral shift of the white point. The result of this shift towards the yellow area of the chromaticity diagram is that the displayed image is yellowish.

  FIG. 35 is a schematic diagram of the optical path through the display from the backlight 40 towards the viewing surface 90 where variable attenuation of light occurs (as a function of wavelength). Light having a predetermined emission spectrum is emitted from the backlight 40. The emitted light forms a boundary 810 between the light emitting surface of the backlight 40 and another medium, which may include, for example, air or other optical elements such as polarizing elements. Cross. Some of the light generated by the backlight may be reflected at the boundary 810 and return to the backlight. This is referred to as “reflection loss”. The second boundary 820 occurs between the medium in which light is currently propagating and the input surface of the display device 60, such as an LC panel. As mentioned above, reflection losses may occur at this boundary. The last two boundaries shown in FIG. 35 are a boundary 830 between the output surface of the display device 60 and the input surface of the image guide 20, and a boundary 840 between the output surface of the image guide 20 and the outside of the display. is there. Further reflection losses may occur at boundaries 830, 840.

  The proportion of incident light that is reflected back at the boundaries 810-840 is primarily determined by the angle of incidence of light for each boundary (the fraction of light reflected at the reference incidence is the lowest) and the respective side of the boundary. Depends on the difference in refractive index between materials. The different the refractive index, the greater the proportion of light reflected back at the boundaries 810-840. Furthermore, if there is a defect in the surface processed along the optical path between the backlight 40 and the viewing surface 90, the scattering of incident light caused by this defect will cause the refractive index of this imperfect surface. Depends on.

  The refractive index of most glasses and polymers, such as injection molded polycarbonate, suitable for use in manufacturing displays, increases as a function of the decrease in light wavelength. Accordingly, it should be understood that the proportion of light scattered or reflected back at the boundaries 810-840 is not uniform across the entire spectrum of light generated by the backlight 40. For polymers with increasing refractive index as a function of decreasing wavelength, most losses occur in the blue region of the spectrum, resulting in a shift of the white point of the display towards the yellow region of the spectrum, and thus The displayed image will turn yellow.

  The light transmission region between the boundaries 810 to 840 may absorb a portion of the light that passes through the boundary. Again, typical polymer materials used in displays absorb light more strongly in the blue region of the visible spectrum, and contribute more to the white point of the display toward the yellow region of the spectrum.

  Additionally, other coloring effects may occur because light of a specific wavelength is selectively transmitted during the passage of light through the display device 60 and the polarizing layer in the optical path.

  As a result of the effects described above, the integral transmission of the optical elements such as the LC display device 60 and the image guide 20 from the backlight along the field of view of the display is not uniform across the spectrum of light. This results in a change in the white point of the display, as shown in FIG.

  It has been recognized that biasing the backlight emission spectrum can compensate for the changing light transmission, and as a result, the white point of the display can be set to a desired value. ing. In this example, a backlight based on a conventional phosphor with an emission spectrum giving a “white source” is used, and as a result, the display is selectively absorbed by blue wavelength light. Is yellowish. In this case, the white point of the display can be returned to the desired white point by increasing the amount of blue phosphor in the backlight. More generally, the effect of the spectral transmission of the system on the color of the output image can be offset by appropriately mixing the three phosphors in the backlight source lamp.

  This technique includes compensating for the wavelength dependent loss and modifying the backlight spectrum so that the white state of the light emanating from the output face of the display can achieve the desired value.

  By measuring the spectral transmission as an integral part of the system, the necessary correction applied to the backlight can be calculated. In particular, by integrating the normalized emission of individual phosphors, the effect of each phosphor on the white state of the display can be separated. By combining the transmission of the system with the resulting white state of the backlight, the visual change of the white point of the display can be calculated. Subsequent relative weighting of the proportions of the individual phosphors can correct the spectral transmission of the system, giving the desired display white point.

FIG. 3 is a schematic isometric rear view of a tiled array of display panels. FIG. 2 is a schematic isometric front view of the array of FIG. 1 is a schematic side view of a display having a light source, a collimator / homogenizer, a display panel, and an image guide. It is the schematic of the backlight apparatus of a fluorescent lamp. FIG. 6 is a schematic diagram of an incident luminance profile at a modulation surface illuminated by a backlight; FIG. 6 is a schematic diagram of an incident luminance profile at a modulation surface illuminated by a backlight; It is the schematic of light emission from a fluorescent lamp. 1 is a schematic view of an improved backlight device having a refractive surface disposed between a fluorescent lamp and a modulation surface. FIG. FIG. 2 is a schematic view of an improved backlight device having a reflective surface disposed between a fluorescent lamp and a modulation surface. FIG. 6 is a schematic view of an improved backlight device having a reflective surface that is perpendicular to the modulation surface and is spatially close to the non-light emitting region of the fluorescent lamp. It is the schematic of the improved backlight apparatus which has a reflective surface on the armor-door structure which is spatially close to the non-light emission area | region of a fluorescent lamp. FIG. 11B is a schematic diagram of air flow through the armor door structure of FIG. 11A. FIG. 3 is a schematic view of an attachment mechanism for coupling an LCD panel to individual image guides. FIG. 12 is a schematic view of various “layers” having the attachment mechanism of FIG. FIG. 12 is a schematic view of various “layers” having the attachment mechanism of FIG. FIG. 12 is a schematic view of various “layers” having the attachment mechanism of FIG. FIG. 3 is a schematic view of a portion of an image guide having a light transmissive guide and bordered by a frame. FIG. 14 is a schematic side view of the image guide and the frame of FIG. 13. FIG. 2 is a schematic view of an outer frame surrounding an image guide and an inner frame having a continuous sheet of material. It is the schematic of the outer frame surrounding an image guide, and the inner frame which has the light transmission guide by which the front end was cut | disconnected. It is the schematic of the optical characteristic of many light transmission guides which have the light absorption layer in the output end, and were bordered by the inner frame isolated from the outer frame. It is the schematic of the optical characteristic of many light transmission guides which have the light absorption layer in the output end, and were bordered by the inner frame fixed to the outer frame. It is the schematic of the optical characteristic of many light transmission guides edged by the inner frame which has a reflection layer which covers all surfaces other than the surface couple | bonded with the light transmission guide and the input surface of an inner frame. FIG. 2 is a schematic view of a single image guide having a frame surrounding an input surface of the image guide. FIG. 3 is a schematic view of a tiled array of image guides held together by a support structure framework. FIG. 21 is a schematic view of a mechanism in which each image guide is securely coupled to the support structure framework of FIG. 20. 1 is a schematic diagram of a system based on two polarizers to enhance contrast by reducing ambient light. FIG. 1 is a schematic diagram of a system based on one polarizing plate to enhance contrast by reducing ambient light. FIG. FIG. 2 is a schematic diagram of a system based on two polarizers for enhancing contrast by reducing ambient light incorporated in a phase modulation layer. FIG. 5 is a schematic diagram of transmitted luminance through an additional polarizer placed in front of the LCD panel and rotated at a constant width. 1 is a schematic diagram of an LCD contrast enhancement system. FIG. FIG. 6 is a schematic diagram of an alternative LCD contrast enhancement system. It is the schematic of the effect of introduce | transducing a polarizing plate into a simple optical flat plate element. 1 is a schematic view of a display screen provided with a conventional electromagnetic wave shield. FIG. FIG. 3 is a schematic view of a display screen having an image guide with an electrically conductive material disposed in a space between light transmissive guides. FIG. 6 is a schematic diagram of how motion artifacts can occur due to motion features represented at the boundary between two adjacent panels of a tiled array of display panels. FIG. 32 is a schematic view of a tiled display that reduces the recognized motion artifacts described with respect to FIG. 31. It is the schematic of the magnitude | size of the asymmetry of the angle of an image guide and an LCD panel. FIG. 5 is a schematic diagram of a progressive shift of light that was initially white through an LCD and image guide array toward yellow. FIG. 6 is a schematic illustration of the attenuation experienced when light from a backlight passes along an optical path through the display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light-emitting surface 20 Image guide 30 Field surface 40 Light source 50 Collimator / monogenizer 60 Liquid crystal panel 70 Image guide 80 Light transmission guide 90 Output surface 110 Non-light-emitting region 120 Light emission expansion region 130a, b Light 150a, b Modulator surface 160 Refractive surface 170 Reflector 175 Light path 180 Reflector 190 Diffuse strip 197, 198 Air flow 210 LCD panel 220 Image guide 230 Base frame 240 First frame 250 Foam tape 260 Second frame 300 Groove 310 Frame 311 Outer frame 312 Inner frame 313 Light Transmission guide 314 Light absorption layer 315 Adhesion layer 316 Reflection layer 331, 332, 333, 334 Ray 331 ′, 332 ′, 333 ′, 334 ′ Ray 331 ″, 332 ″, 333 ″, 334 ″ Ray 36 0 Image output surface 380 Light transmission guide 410 Base frame 415 Support frame 420 Strip 425 Clearance hole 430 Strut 440 Crinkle washer 450 Screw 460 Spacer 470 Image guide 471 Output end 490 Washer 495 Strut 510, 510 ′ LCD
520, 520 ′, 521, 530 Polarizer 540 Phase modulator 570 Image guide 580 Glass sheet 585 Non-reflective coating 590 Polarizer 610 Electrical conduction shield 620 Transparent electrical conduction layer 640 Strip 701 Static line 702 Movement line 705 Tile boundary 707 Movement Line traveling direction 710 Scanning direction 720 Top row 725 Bottom row 730 Panel 810, 820, 840, 850 Boundary

Claims (58)

A display device having an image output surface on which an image is displayed as an array of spaced pixel elements;
An image guide coupled to an image output surface of the display device and having a plurality of light transmission guides each having an input end and an output end, wherein one or more groups of the light transmission guides are one of pixel elements. A display comprising an image guide in which input ends of a plurality of light transmission guides are arranged relatively to each other so as to receive light from each of the above groups,
In the display, for clusters having at least one subset of the light transmission guides,
At the outer edge of the cluster, the input end of the light transmissive guide has optical characteristics substantially similar to the optical characteristics of the light transmissive guide and is arranged to receive light from the image output surface of the display An inner frame having a surface and an outer frame having a thermal expansion characteristic substantially similar to that of the light transmission guide,
The inner frame is optically coupled to each adjacent light transmission guide, and the surface of the inner frame and the surface of the inner frame adjacent to the outer frame are located at positions opposite to the input surface of the inner frame. The light that enters the inner frame and strikes the reflective layer passes through a part of the inner frame optically coupled to an adjacent light transmission guide, or of the inner frame. A display that reflects off the inner frame through an input surface.   The inner frame has a number of light transmissive guides, and a reflective coating is disposed within the inner frame and the portion of each light transmissive guide in the inner frame optically coupled to an adjacent light transmissive guide. The display according to claim 1, wherein the display covers substantially all surfaces of each light transmission guide in the inner frame other than an input surface of each light transmission guide.   The multiple light transmissive guides in the inner frame are formed in multiple adjacent rows along each side of the inner frame, each row being optically coupled to an adjacent row. The display according to claim 2.   The display according to claim 2, wherein an output end of the light transmission guide in the inner frame is cut off.   The display of claim 1, wherein the inner frame has a continuous boundary of material.   The display according to claim 1, wherein the reflective layer is a vapor-deposited metal layer.   The display according to claim 1, wherein the reflective layer is a metal adhesive tape. A display device having an image output surface on which an image is displayed as an array of spaced pixel elements;
A light transmissive element having a field surface, arranged to receive light from the display device, comprising a light transmissive element for displaying the received light on the field surface;
The light transmissive element has a polarizing layer disposed in an optical path between the display device and the field plane;
A display in which the polarizing layer is arranged to attenuate unpolarized ambient light received from outside the display while substantially transmitting polarized light received from the display device.   The display of claim 8, wherein the polarizing layer is optically coupled to the light transmissive element in a plane.   The display of claim 9, wherein the polarizing layer is optically coupled to a surface of the light transmissive element adjacent to the display device.   The display according to claim 8, wherein the light transmissive element is a transparent sheet.   The display according to claim 11, wherein the transparent sheet is a glass sheet or a plastic sheet.   The display according to claim 12, wherein the transparent sheet is a touch panel or a loudspeaker device.   14. A display according to any one of claims 8 to 13, further comprising a non-reflective layer coupled to the surface of the light transmissive element at the image output surface of the display.   The display of claim 14, further comprising a non-reflective layer coupled to the polarizing layer of the light transmissive element.   The light transmissive element is an image guide having a plurality of light transmissive guides each having an input end and an output end, and the input end of the light transmissive guide receives light from each group of one or more pixel elements. The display according to claim 8, which is arranged to receive light.   The display of claim 16, further comprising a polarizing layer coupled to the display device and arranged in the polarizing layer of the light transmissive element.   18. A display according to any of claims 16 or 17, further comprising a phase modulator coupled to the polarizing layer of the light transmissive element.   19. A display according to any one of claims 16 to 18, further comprising a phase modulator coupled to the display device. A backlight having a light emitting region and a non-light emitting region;
A modulator arranged to receive light emitted from the backlight;
Light redirecting means arranged to redirect a part of the light emitted from the light emitting area of the backlight onto the area of the modulator in close relation to the non-light emitting area of the backlight; Backlit display. The backlight comprises one or more fluorescent lamps;
21. The display of claim 20, wherein each of the fluorescent lamps has a continuous light emitting area, and at least one end of the continuous light emitting area terminates in a non-light emitting area.   22. A display as claimed in claim 20, wherein the light redirecting means comprises one or more reflective elements.   23. A display as claimed in any one of claims 20 to 22, wherein the light redirecting means comprises one or more refractive elements.   The display according to any one of claims 20 to 23, wherein the light redirecting means is disposed between the light emitting region of the backlight and the modulator.   The display according to any one of claims 20 to 22, wherein the light redirecting means is disposed outside the light emitting region of the backlight.   26. The display according to claim 25, wherein the reflective element is arranged in an armor door structure so that airflow between the backlight and the modulator can pass through an opening of the reflective element.   27. A display as claimed in any one of claims 20 to 26, wherein the means for redirecting light comprises a number of separate strips of material.   27. A display as claimed in any one of claims 20 to 26, wherein the means for redirecting light comprises a number of strips arranged or molded in a sheet of optically transparent material. A display panel having an image output surface on which an image is displayed as an array of spaced pixel elements;
Each is a light transmission guide having an input end and an output end, wherein the input end is arranged to receive light from each group of one or more pixel elements, and a base frame surrounds the input end An image guide having multiple light transmission guides;
A first frame having an opening and firmly attached to the base frame, wherein the display panel is disposed with respect to the image guide within the opening of the first frame;
A second frame having an opening smaller than the first frame, overlapping the display panel and applying pressure to the display panel, thereby holding the display panel close to the image guide; A display having a second frame elastically coupled to the first frame.   30. The display of claim 29, wherein the base frame and the first frame are formed as a single structure with each other.   The second frame is not rigid in a direction perpendicular to the plane of the display panel than both the display panel and the first frame, and the second frame is in a direction perpendicular to the plane of the display panel. 31. The display according to claim 29, wherein a force is applied to the display panel by the second frame in the direction of the image guide due to the distortion.   The display according to any one of claims 29 to 31, wherein an input surface of the image guide protrudes from a surface of the base frame.   The display according to any one of claims 29 to 32, wherein the first frame and the second frame are coupled to each other via an intermediate layer.   The display of claim 33, wherein the intermediate layer flexibly couples the second frame to a display screen.   35. A display as claimed in any one of claims 29 to 34, wherein the first frame comprises a number of separate elements.   36. A display as claimed in any one of claims 29 to 35, wherein the second frame comprises a number of separate elements.   37. The display of claim 36, wherein the second frame overlaps the first frame such that separate elements of the first frame and the second frame are coupled together as a single unit.   38. One or more of the base frame, the first frame, and the second frame inhibit light leakage from around the edge of the display panel into the image guide. Display as described.   The second frame has a light reflecting or diffusing surface on a side surface facing the backlight, and the light hitting the light reflecting or diffusing surface can be redirected toward the backlight. The display according to item. A plurality of light transmission guides having an input and an output end, and a base frame having a thermal expansion coefficient substantially matching a thermal expansion coefficient of the light transmission guide, the base frame surrounding the input end of the light transmission guide; A number of image guides each having
Means for coupling the plurality of image guides to an array in which an output surface of the image guide forms a continuous surface;
A support frame that is harder than the base frame and has a different coefficient of thermal expansion from the base frame, in a plane between the base frame and the support frame that is substantially parallel to the output surface of the image guide. A display having a support frame that couples the base frame to the support frame by connecting means that allow relative movement.   41. The display of claim 40, wherein the image guides are directly coupled to each other.   42. A display as claimed in claim 40 or claim 41, wherein the support frame comprises struts and the base frame is coupled to the struts.   43. A display according to claim 42, wherein the struts are arranged in cavities formed between adjacent image guides and individual base frames.   43. The display of claim 42, wherein the strut is at least partially embedded in the base frame.   The frictional properties of the surfaces of the base frame and other structures in the display that may move differently under conditions of thermal expansion are due to the lateral forces due to the different expansion of the display distorting the base frame. 45. A display as claimed in any one of claims 40 to 44, characterized in that it has a characteristic that is less than the force required for it. A display device having an image output surface on which an image is displayed as an array of spaced pixel elements;
An image guide coupled to an image output surface of the display device and having a plurality of light transmission guides each having an input end and an output end, and the input ends of the light transmission guides are disposed relative to each other. Thus, a display having one or more groups of light transmissive guides and an image guide that receives light from an individual group of one or more pixel elements,
In the display, an electrically conductive material is provided along the length of at least a portion of at least a subset of the light transmissive guide, and the electrically conductive material absorbs electromagnetic waves emitted from the display device. The display is arranged such that the electrically conductive material between the light transmissive guides in separate areas of the image guide is electrically connected to each other.   The display of claim 46, wherein the electrically conductive material comprises a plastic strip filled with carbon.   48. A display as claimed in claim 46 or claim 47, wherein the electrically conductive material comprises a wire.   49. The display of claim 48, wherein the wire is formed as a wire mesh.   50. A display according to any one of claims 46 to 49, further comprising a conductive shield surrounding an area that is not a screen of the display and to which the electrically conductive material is electrically connected. Multiple display panels formed into multiple columns and arranged to form a single image output surface, each display capable of displaying multiple lines of pixels;
A tiled display having display control means arranged to refresh each display panel on a line-by-line basis in accordance with a refresh pattern,
A set of refresh patterns vertically adjacent to the display panel is substantially the same as the lower region of the upper set of display panels is refreshed, substantially simultaneously with the upper region of the lower set of display panels. A tiled display that is a refresh pattern that refreshes the area.   Adjacent columns of alternating display panels are refreshed, line by line, sequentially from the top line to the bottom line of each display in the column, with respect to the first column of the display panel. 52. The display of claim 51, wherein the display is refreshed sequentially from line to line from the bottom line of each display in the column.   53. The display panel of claim 52, wherein the display panels in staggered rows are rotated 180 degrees with respect to adjacent columns of display panels in the plane of the image output surface, and the rotated display panels are provided with an inverted image. display.   53. The display of claim 52, wherein successive columns of alternating display panels use a top-to-bottom addressing scheme and a bottom-to-top addressing scheme. A transmissive display device having an image output surface on which an image is displayed as an array of spaced pixel elements,
Spectral loss in the visible spectrum of the display device is a transmissive display device that becomes stronger towards the blue end of the visible spectrum;
A backlight for providing illumination of the display device,
A backlight type display having a backlight in which visible light emission from the backlight is dominant at a blue end of the visible spectrum.   56. The display of claim 55, comprising a light transmissive element having a field surface, the light transmissive element receiving light from the display and displaying the received light on the field surface.   The light transmissive element is an image guide that is coupled to an image output surface of the display device and includes a plurality of light transmissive guides each having an input end and an output end, and the input ends of the light transmissive guides are mutually connected. 57. The display of claim 56, wherein the display is relatively disposed, and the group of one or more light transmission guides receives light from an individual group of one or more pixel elements.   58. A display as claimed in any one of claims 55, 56 or 57, wherein the backlight comprises one or more phosphor lamps.

Images